In condition control equipment, particularly in temperature regulating systems, it is desirable to be able to adjust the sensing element, its associated circuitry, and the electronics to provide functions which will match and properly control various types of heating and cooling loads. In the electronic control of heating and cooling equipment it is often desirable to be able to adapt one condition responsive system to control various types of heating loads, such as gas fired furnaces, oil fired furnaces, and electrically heated furnaces. This same temperature or condition control equipment is used to control various types of air conditioning compressors which may involve a single compressor, or staged and variable speed compressors to vary the cooling, as the circumstances dictate. In the past it has been difficult to design a single condition responsive or temperature control system and its associated electronics which will match various loads with a minimum of alteration in the circuitry.